Four-stroke-cycle internal-combustion engine



1,511,338 w. c. HOLDERNESS I FOUR-STROKE CYCLIE INTERNAL COMBUSTION ENGINE @ct, M, 1924.

Filed Nov. 2. 1921 MAW Q Patented @ct. I4 11%24.

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Wm GYBHA HOLDERNESS, 0F PETERSHAM, NEW SQUTH WALES, AUSTRALIA.

FUR-STROKE-GYCLE INTERNAL-COMBUSTION ENGINE.

Application filed November This invention relates to four-stroke cycle internal combustion engines. It refers particularly to that type of such engines whose cylinders have L-shaped heads in which the inlet and exhaust valves are arranged laterally of each other. I

The object of the invention is to provide means in connection with such engines whereby a more eflicient'oombustion of explosive mixture admitted to the engine cylinder or cylinders is efl'ected, resulting in increased power and saving of fuel in the running of saidengines.

In one embodiment of the invention the head of the piston is formed with a slope or incline disposed in direction towards the inlet valve through which the explosive mixture is admitted to the engine cylinder.

Another embodiment of the invention consists in forming the top wall of the clearance space with a slope or incline arranged opposite to the inlet valve but disposed in a direction opposite to the slope or incline of the piston.

A further embodiment of the invention consists in forming the piston and the top wall of the clearance space respectively with a slope or incline as before indicated but varying the de ree of slope to ensure that the combined s opewill equal approximately the slope formed on either the piston head or the top wall of the clearance space separately.

In each case the sloping or inclination is so disposed in relation to the inlet valve of the engine that the height of the clearance space towards the inlet valve will be greater than the height of such space remote from said valve when the piston is disposed at the upper portion of the cylinder.

Referring to the accompanying drawings in which embodiments of the invention are illustrated, Fig. 1 is a broken vertical sectional view of the head of an engine cylinder with a piston with inclined head therein; Fig. 2 a view similar to Fig. 1 but showing the head of the piston horizontal and the top wall of the clearance space inclined; Fig. 3 a view 1921. Serial No. 512,209.

I similar to Figs. 1 and 2 but in which both the head of the piston and the top wall of the clearance space are inclined; Fig. 4 a longitudinal section of the engine cylinder on line a1a Fig. 1; and Figs. 5 to 12 detail views illustrating types of pistons usable in connection with the invention.

The invention is mainly applicable to engine cylinders having L-shaped heads in which the inlet valves through which explosive mixture is admitted to the cylinders and the exhaust valves through which prodnets of combustion are discharged from the cylinders are arranged sidewise of each other. In Fig. 1 the piston 1 is formed with an incline 2. Such incline is disposed towards the inlet valve 3. It is preferred though not essential that the horizontal central axis of the piston directed towards the inlet valve 3 be set'in line with the centre of the said valve as shown by line bb Fig. 4.

Located laterally of the inlet valve 3 is the ex haust valve 4. The valves 3 and 4 open up wardly into the cylinder 7.

Instead of forming the piston l with an inclination the top wall of the clearance space 5 may be provided with an incline 6. The incline 6 relative to the inlet valve 3 is disposed in opposite direction tothe incline 2 (Fig. 1) of the piston 1; said incline is furnished on the top wall of the clearance space directly opposite to the inlet valve 3.

An alternative construction of the top wall of the clearance space and the piston to that shown in Figs. 1 and 2 is illustrated in Fig.

3, wherein both the said wall and piston are provided with an incline; it is preferred that the incline in each case be made of such degree to approximately coincide with half the degree of incline on either the said wall or piston as shown in Figs. 1 and 2.

It is essential that the slope or incline be arranged so that the height of the clearance space near the inlet valve will be greater than the height of such space which is distant from the said valve as is shown in Figs. 1 to 3, the piston 1 in these figures being disposed at the top of thecylinder 7. In such position of the piston 1 the clearance space 5 assumes the shape of a wedge and the base of the wedge is towards the inlet valve 3. A slope or incline approximately of 9 to 21 millimetres in 3 inches has been found suitable but this may be varied within limits.

The face of the head of the inclined piston 1 may be plane as shown in Figs. 1 to 3 or it may be convexed or concaved. Figs. 5 and 6 and 11 and '12 show the head of the piston convexed and Figs. 7 to show the head of the piston concaved. The axis of the curve generated on the head of the pistons shown in Figs. 5 and 6 and 9 and 10 may be on a line b-b Fig.4, whilst the axis of the curve generated on the head of the pistons shown in Figs. 7 and 8 and 11 and 12 may be on a line at right angles to said line bb.

In practice it has been found that when engines are provided with means in accordanc with the invention the explosive mixture burns quicker as the speed of the piston increases and that it burns slower as the speed .of the piston decreases. This is advantageous in the running of engines inasmuch as when the engines are working at slow speed they are enabled to workeitectively without knocking and to give more power than engines at' present in use. Further, as the speed of the piston increases, even up to maximum velocity, the speed of burning of the explosive mixture increases and complete combustion thereof is effected before the piston reverses for its power stroke and increased power from the engine is thus ensured. Such increase in power is approximately in direct ratio to the piston speed and is greater than the power derived from engines at present known. As the varying degrees of combustion of the explosive mixture is dependent on piston speed approximately full spark advance may be.

tion engine provided with a cylinder or cylinders having L-shaped head and inlet and exhaust valves disposed in such head laterally of each other and" opening upwardly therein, characterized in that the top wall of the clearance space opposite to the inlet valve and the head of the piston are inclined in opposite'directions whereby whensaid piston is disposed in the upper portion of said cylinder the height of the clearance space proximate said. inlet valve is greater than the height of said space distant from I gaicil inlet valve for the purpose herein speci- 3. A four-stroke cycle internal combustion engine provided with a cylinder or cylinders having L-shaped head and inlet and exhaust valves disposed. in such head laterally; of each other and opening upwardly therein, characterized in that the head of the piston is formed with a plane surfaced incline which is disposed in a direction toward the inlet valve whereby the centre of said incline will lie on a line directed from the centre of said inlet valve and when'said piston is disposed. in the upper portion of said cylinder the height of the clearance space proximate said inlet valve is greater than the height of said space distant from said valve for the purpose hereinspecified.

In testimony whereof I aifix my signature.

WILLIAM CYRIL HOLDERNESS. 

